1. Field of the Invention
The subject invention relates to a fluid filtration device, and more particularly, to an encapsulated filter cartridge having a permanently sealed sump, configured to accommodate a filter assembly. The filter assembly includes a carbon block filter element and a microporous filter element. The microporous filter element of the filter assembly may be, for example, a hollow microporous fiber subassembly housed within the axial cavity of the carbon block element or a pleated filter element surrounding the radially outer surface of the carbon block filter element.
2. Background of the Related Art
In most areas of the world, drinking or tap water contains significant amounts of harmful or offensive chemicals, suspended particulate matter, and microorganisms. In a variety of circumstances, these contaminants must be removed before the water can be used. Although municipal water treatment plants attempt to address this problem, many individuals and organizations find such efforts insufficient and utilize on-site water filters. Frequently, such water filters are integrated into appliances, such as ice makers of refrigerators or water dispensers.
Filter elements containing activated carbon are known to be effective in removing chemicals from water, e.g., chlorine, hydrogen sulfide, pesticides, herbicides, phenol, chlorophenol and hydrocarbon. Removal of such contaminants usually improves the taste, odor and appearance of the filtered water. Nonetheless, most carbonaceous filter elements are not fine enough to remove bacteria, viruses or other microorganisms. For that purpose, various microporous filter elements have been incorporated into filtration devices in addition to carbonaceous filter elements. Microporous filter elements known to be effective at removing bacteria, viruses, and other microorganisms include hollow microporous fibers, such as those described in the U.S. Pat. No. 3,526,001 (the disclosure of which is incorporated by reference herein), microporous membranes, such as those described in the U.S. Pat. No. 6,113,784 (the disclosure of which is incorporated by reference herein), and other structures capable of performing a similar function.
Typically, on-site filters are designed to be mounted in a permanent housing coupled to a fluid stream, e.g., in series with a pipe, and include some means of access to the filter cartridge inside the housing for replacing such cartridge when needed. Another way of coupling fluid filters to a fluid stream is by way of countertop filtration units. A countertop filtration unit is a portable apparatus dimensioned to fit on a standard household countertop adjacent to the sink and adapted for coupling to a fluid flow outlet, such as a faucet.